The University Archives are retained in the John J. Burns Special Collections Library at Boston College and are non-circulating (these materials cannot be borrowed, but can be used in the Reading Room).
Don't forget that BC's Burns Library has a very large collection of archival material related to literary figures and topics.
The numerous special collections and archives in greater metropolitan Boston means that the literary scholar has tremendous opportunities for accessing important original primary sources.
To help ascertain what primary material local (and other) libraries hold, the following databases are very useful:
John Gower shooting the world, a sphere of earth, air, and water (from a manuscript of his works ca. 1400)